So while the OG MC basically dressed up as someone else, she had guests come in outfits inspired by her!

A source dished some deets about the big bash, revealing:

"Over the weekend, Mariah threw a party in the house she was staying in in Lake Como, Italy, About 40 to 50 people — people from her touring crew, friends — dressed up in their favorite Mariah looks; looks inspired by her songs or videos, with Mariah hair, poses, and her signature style."

LOLz!

We're not exactly sure what the occasion was, especially with Mariah's birthday being nearly a month ago, but it sounds like it was a lot of fun!